Early-Transition-Metal Complexes of Functionalized Nonagermanide Clusters: Synthesis and Characterization of [Cp-2(MeCN)Ti(eta(1)-Ge-9{Si(TMS)(3)}(3))] and K-3[Cp2Ti(eta(1)-Ge-9{Si(TMS)(3)}(2))(2)]

摘要

Anionic clusters with a homoatomic [Ge-9] core are species with Ge atoms in low oxidation states. In this study their reaction with early-transition-metal complexes was investigated. We report the syntheses of Ti(III) complexes of silylated [Ge-9] Zintl clusters, which are rare examples of molecular complexes with Ge-Ti interactions. The neutral species [Cp-2(MeCN)Ti(eta(1)-Ge-9{Si(TMS)(3)}(3))] (1) was obtained by the reaction of K[Ge-9{Si(TMS)(3)}(3)] with [Cp2TiCl](2) in toluene as dark orange crystals, whereas the reaction of K-2[Ge-9{Si(TMS)(3)}(2)] with [Cp2TiCl](2) in thf and subsequent recrystallization from toluene resulted in dark green crystals of K-3[Cp2Ti(eta(1)-Ge-9{Si(TMS)(3)}(2))(2)] (2). Compound 2 contains the trianion [Cp2Ti(eta Ge-1(9){Si(TMS)(3)}(2))(2)](3-) (2a), which can be described either as a [Cp2Ti](+)-bridged [Ge-9{Si(TMS)(3)}(2)](2-) dimer or as a heavily distorted tetrahedral Ti(III) complex bearing two germanide cluster ligands. Both compounds display donor-acceptor interactions between single Ge vertex atoms of the [Ge-9] clusters and Ti(III). Compounds 1 and 2 were characterized by single-crystal X-ray diffraction, EPR spectroscopy, and elemental analysis.